Data on the incidence and prevalence of sexual aggression were obtained through the use of a 10-item sexual experiences survey (Koss and Oros, 1982; Koss and Gidycz, 1985). A total of 15.4 percent of the women reported experiencing an act that met legal definitions of rape, and 4.4 percent of the men reported committing such acts. Incidents encompassed those experienced or perpetrated since age 14. The victimization rate for women based on these data was 38/1,000, 10-15 times greater than rates based on the National Crime Survey. Because virtually none of the victims or perpetrators had been involved with the criminal justice system, their experiences qualify as "hidden rape." 7 tables, 26 references.